The egg, larval, and pupal stages of the plusiine moth Autographa pseudogamma (Grote, 1875) are discussed and illustrated based on a laboratory iso-female rearing of a wild moth collected near Big Sky, Montana, in mid-July 2016. Eggs, larval coloration and pattern, and pupae are very similar to those already known from close relatives in the genus Autographa Hübner, [1821]. DNA sequence data from the COI barcode region were used to generate a phylogenetic tree showing the position of A. pseudogamma amongst other North American members of the genus and to help confirm the identification of field-collected moths. Genetic analyses indicate that A. pseudogamma is most closely related to A. sansoni Dod, 1910, contrary to relationships previously generated based on morphology.